// Copyright 2014 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "content/renderer/java/gin_java_bridge_dispatcher.h"

#include "base/auto_reset.h"
#include "base/strings/string_number_conversions.h"
#include "base/strings/utf_string_conversions.h"
#include "content/common/gin_java_bridge_messages.h"
#include "content/public/renderer/render_frame.h"
#include "content/renderer/java/gin_java_bridge_object.h"
#include "third_party/WebKit/public/web/WebLocalFrame.h"
#include "third_party/WebKit/public/web/WebView.h"

namespace content {

GinJavaBridgeDispatcher::GinJavaBridgeDispatcher(RenderFrame* render_frame)
    : RenderFrameObserver(render_frame)
    , inside_did_clear_window_object_(false)
{
}

GinJavaBridgeDispatcher::~GinJavaBridgeDispatcher()
{
}

bool GinJavaBridgeDispatcher::OnMessageReceived(const IPC::Message& msg)
{
    bool handled = true;
    IPC_BEGIN_MESSAGE_MAP(GinJavaBridgeDispatcher, msg)
    IPC_MESSAGE_HANDLER(GinJavaBridgeMsg_AddNamedObject, OnAddNamedObject)
    IPC_MESSAGE_HANDLER(GinJavaBridgeMsg_RemoveNamedObject, OnRemoveNamedObject)
    IPC_MESSAGE_UNHANDLED(handled = false)
    IPC_END_MESSAGE_MAP()
    return handled;
}

void GinJavaBridgeDispatcher::DidClearWindowObject()
{
    // Accessing window object when adding properties to it may trigger
    // a nested call to DidClearWindowObject.
    if (inside_did_clear_window_object_)
        return;
    base::AutoReset<bool> flag_entry(&inside_did_clear_window_object_, true);
    for (NamedObjectMap::const_iterator iter = named_objects_.begin();
         iter != named_objects_.end(); ++iter) {
        // Always create a new GinJavaBridgeObject, so we don't pull any of the V8
        // wrapper's custom properties into the context of the page we have
        // navigated to. The old GinJavaBridgeObject will be automatically
        // deleted after its wrapper will be collected.
        // On the browser side, we ignore wrapper deletion events for named objects,
        // as they are only removed upon embedder's request (RemoveNamedObject).
        if (objects_.Lookup(iter->second))
            objects_.Remove(iter->second);
        GinJavaBridgeObject* object = GinJavaBridgeObject::InjectNamed(
            render_frame()->GetWebFrame(), AsWeakPtr(), iter->first, iter->second);
        if (object) {
            objects_.AddWithID(object, iter->second);
        } else {
            // Inform the host about wrapper creation failure.
            render_frame()->Send(new GinJavaBridgeHostMsg_ObjectWrapperDeleted(
                routing_id(), iter->second));
        }
    }
}

void GinJavaBridgeDispatcher::OnAddNamedObject(
    const std::string& name,
    ObjectID object_id)
{
    // Added objects only become available after page reload, so here they
    // are only added into the internal map.
    named_objects_.insert(std::make_pair(name, object_id));
}

void GinJavaBridgeDispatcher::OnRemoveNamedObject(const std::string& name)
{
    // Removal becomes in effect on next reload. We simply removing the entry
    // from the map here.
    NamedObjectMap::iterator iter = named_objects_.find(name);
    DCHECK(iter != named_objects_.end());
    named_objects_.erase(iter);
}

void GinJavaBridgeDispatcher::GetJavaMethods(
    ObjectID object_id,
    std::set<std::string>* methods)
{
    render_frame()->Send(new GinJavaBridgeHostMsg_GetMethods(
        routing_id(), object_id, methods));
}

bool GinJavaBridgeDispatcher::HasJavaMethod(ObjectID object_id,
    const std::string& method_name)
{
    bool result;
    render_frame()->Send(new GinJavaBridgeHostMsg_HasMethod(
        routing_id(), object_id, method_name, &result));
    return result;
}

std::unique_ptr<base::Value> GinJavaBridgeDispatcher::InvokeJavaMethod(
    ObjectID object_id,
    const std::string& method_name,
    const base::ListValue& arguments,
    GinJavaBridgeError* error)
{
    base::ListValue result_wrapper;
    render_frame()->Send(
        new GinJavaBridgeHostMsg_InvokeMethod(routing_id(),
            object_id,
            method_name,
            arguments,
            &result_wrapper,
            error));
    base::Value* result;
    if (result_wrapper.Get(0, &result)) {
        return std::unique_ptr<base::Value>(result->DeepCopy());
    } else {
        return std::unique_ptr<base::Value>();
    }
}

GinJavaBridgeObject* GinJavaBridgeDispatcher::GetObject(ObjectID object_id)
{
    GinJavaBridgeObject* result = objects_.Lookup(object_id);
    if (!result) {
        result = GinJavaBridgeObject::InjectAnonymous(AsWeakPtr(), object_id);
        if (result)
            objects_.AddWithID(result, object_id);
    }
    return result;
}

void GinJavaBridgeDispatcher::OnGinJavaBridgeObjectDeleted(
    GinJavaBridgeObject* object)
{
    int object_id = object->object_id();
    // Ignore cleaning up of old object wrappers.
    if (objects_.Lookup(object_id) != object)
        return;
    objects_.Remove(object_id);
    render_frame()->Send(
        new GinJavaBridgeHostMsg_ObjectWrapperDeleted(routing_id(), object_id));
}

void GinJavaBridgeDispatcher::OnDestruct()
{
    delete this;
}

} // namespace content
